The xi apparently has a 15mm rear sway unlike the i which has a 13mm. I was wondering if I should not get a UUC or M3 rear sway now since the install is long and hard.

For my list of stage 2 (Front and rear sways bars, rear chassis brace, front strut brace, m3 parts) is there anything that should NOT be added. Since there is a limited number of xi parts, there has to be a perfect list of what to add or not add.

BMW Performance Springs... not for 335i, 335xi...
there aren't much options for E90-335xi-09.... I checked daily on the web, BMW specialist....
Seems, Dinan S-pack, or suspension system is the $$ way but not the muffler, many feel like its like made in China quality!!